The invention relates to magnetic cards and, in particular, to a method and an apparatus for determining the authenticity of a magnetic card.
Magnetic cards can be used, in association with an appropriate read/writer, in a vast array of different environments. For example, magnetic user identification cards are commonly used in financial transactions, such as those conducted at automated teller machines (ATMs) to withdraw cash from a user's account, or at point of sales terminals in retail and other commercial establishments to purchase goods or services. Such magnetic cards incorporate a magnetic stripe which runs the length of the card adjacent one edge, the magnetic stripe having a series of tracks (normally three) in which data such as the user's account details, authorized transaction limit, expire date, and in some cases an encrypted personal identification number (PIN) is stored.
Due to their convenience, the use of such magnetic cards in financial transactions is becoming increasingly popular, with ATMs now replacing visits to traditional financial institutions for the cash requirements of many customers, and with point of sales terminals allowing cashless payment by credit or debit cards in the majority of shops, restaurants etc. As a consequence however, the level of fraud associated with the use of magnetic cards in financial transactions has also increased, especially at point of sales terminals where only a signature is required along with a card in order to carry out a transaction. When such cards are lost or stolen, the owner will normally become aware that the card is missing after a relatively short period of time and report this to the relevant authorities so that further use of the card can be prevented.
It has been known for criminals to produce counterfeit magnetic cards on which the user identification data which is stored on an authentic card has been copied. Such a counterfeit card may be used in financial transactions without the knowledge of the owner of the authentic card whose user identification data has been obtained by some means and copied to the counterfeit card. In some instances, even the personal identification number (PIN) associated with the authentic card has been obtained, allowing the counterfeit card to be used in transactions where a PIN is required, such as to obtain cash at an automated teller machine (ATM). As the techniques and equipment used by criminals become increasingly sophisticated, these counterfeit cards are often indistinguishable from the authentic card to the eye, and where the magnetic data has been copied accurately, a card reader may also be incapable of recognizing that the card is not authentic. The existence of a counterfeit card may go undetected for some time, until the owner of the authentic card realizes that money has been debited from his account for transactions that he did not carry out. In the meantime, the fraudster may continue to use the counterfeit card to obtain considerable funds or to make purchases. Moreover, it is often difficult to prove the existence of a counterfeit card.